Typically, a standard shell mill style milling cutter is fastened to an adaptor by a commercially available socket head cap screw, as shown in FIG. 6.
There are occasions in product development where design constraints of the milling cutter prohibit the use of a conventional fastener. As shown in FIG. 7, one example would be a small diameter milling cutter with a large cutting insert and the counter bore required in the milling cutter for the head 39 of the fastener would invade the pocket and the chip gash areas 38 and produce a weak cutter design.
The existing practice that is used to address this problem is to use a special fastener that consists of threads on both ends. These threads are different diameters and pitch. The milling cutter also requires a threaded portion in the bore, as shown in FIG. 8. This type of attachment requires special (time consuming) instructions to be suppled to the user. These instructions have a margin for user error, which can result in tool failure.